Liquid fluorocarbons have a high affinity for oxygen and can dissolve or solubilize significant quantities of oxygen. For this reason, fluorocarbon emulsions have been used as biocompatible oxygen carriers and/or blood substitutes.
Fluorocarbon liquids have also been used as radiological imaging agents. See e.g., U.S. Pat. Nos. 3,975,512 and 4,987,154. Fluorocarbon liquids have also been used in magnetic resonance imaging. See e.g., U.S. Pat. No. 4,951,673.
In many instances it is desirable to directly visualize animal tissues or cells. Staining of tissues with tissue-specific dyes is a common histological technique. However, for certain tissues and cells, such as those reticuloendothelial (RES) system, there remains a need for better visualization techniques. A surgeon, for example, may use a radiological lymphographic technique to prepare presurgical films or pictures which indicate the location of lymphatic tissue in a patient. However, during surgery, working in the surgical incision, it may be more difficult to differentiate the tissue in question.
Similarly, in research applications, it is often desirable to identify and label certain tissues, such as RES tissues.
The present invention provides a ready mechanism for locating and visually identifying certain cells and tissues.